FlytrapCare Carnivorous Plant Forums

As said previously, they stress with any change in environment and can take weeks to months to recover. Just give it some time.
However, in my experience, feeding them as new pitchers develop will help them grow faster. Where yours are already producing pitchers, that shows it's well on it's way to recovery. Also in my experience, what you feed them will definitely have an impact.
If you feed them chemical food (fertilizer), you'll see slightly faster growth, but they may skip forming a pitcher on up to the next three leaves (usually only a single leaf skip). Not a big deal if you want size faster, but the top may outpace the bottom, and that can produce other problems.
If you feed it natural food (bugs) they'll grow slightly slower, but will grow a pitcher on each new leaf to catch more bugs. They'll also grow more proportionally, the bottom keeping up with the top, but may lead to the need for a repot more quickly.
Either way, you may have to add a little water to the first pitchers to encourage the bugs to decompose or the fertilizer to dissolve. After that, if you keep enough water in the media (not sitting in water), they should keep fluid in the pitchers themselves.